Coronal Shear Fractures of the Distal Humerus: A Review of Diagnosis, Treatment, and Outcomes

Abstract

Fractures of the capitellum and trochlea are uncommon fractures of the elbow and can be challenging to treat due to their size, location, and articular nature. Because of their intra-articular nature and predilection toward displacement, these fractures are typically treated operatively. Furthermore, capitellum fractures have high rates of associated injuries, including radial head fractures or lateral collateral ligament injury in ~30% to 60% of patients. In addition to open reduction internal fixation, operative options include fragment excision, arthroscopic assisted reduction and fixation, and elbow arthroplasty. In this article, we undertake a comprehensive literature review of capitellum fractures of the distal humerus, in an attempt to summarize the existing body of evidence and propose areas of future study.

Keywords: capitellum; coronal shear fracture; distal humerus fracture; elbow fracture; trochlea.

Figure 1.

Radiograph showing a coronal shear fracture of the capitellum with fracture displacement of greater than 90 degrees.

Figure 2.

Surgical images of an articular shear fracture of the capitellum. A lateral exposure of the elbow was performed on the patient shown in Figure 1 using a modified Kaplan approach by splitting between the ECRB and ECRL (the hand is distal to the left and the shoulder is distal to the right). (a) A displaced articular shear fracture involving only the capitellum (Dubberly type 1A) is visible, rotated 90 degrees from its anatomic position. (b) The fracture has been reduced and fixed with two headless compression screws placed anteriorly to posteriorly (not shown), restoring the radiocapitellar alignment. R = radial head, C = capitellum.

Figure 3.

Postoperative anteroposterior (AP) and lateral elbow radiographs of the same patient from Figures 1 to 3. (a) AP and (b) lateral x-rays show anteroposterior Herbert-style headless compression screw fixation of the capitellum.

Figure 4.

Injury, operative, and postoperative images of Dubberly 3B fracture treated with olecranon osteotomy. (a) Injury radiographs, with lateral showing classic “double arc” sign. (b) Three-dimensional computed tomography reconstructions better show capitellar comminution with lateral condyle and trochlear involvement. (c) Intraoperative photo showing exposure via trans-olecranon approach. (d) Fluoroscopy showing placement of posteroanterior headless compression screws, posterolateral distal humerus plate, and 6.5-mm cannulated screw for olecranon osteotomy repair.

Figure 5.

Osteonecrosis of the capitellum treated with hardware removal. (a) 3-month postoperative radiographs of patient showing in Figure 4, showing collapse of the capitellum with intraarticular screws. (b) Radiographs status post removal of humeral hardware and capsular release.